Steering columns for motor vehicles have a steering shaft with a steering spindle, on the rear (in the driving direction) end of which, which faces the driver, a steering wheel is attached for the introduction of manual steering commands by way of the driver. The steering spindle is mounted rotatably in a supporting unit which is connected to the vehicle body.
The steering wheel has fastening means, by way of which the steering wheel hub is coaxially fastened fixedly on the rear end (which faces the driver) of the steering spindle so as to rotate with it, the longitudinal axis of the steering wheel hub being identical to the axis of the steering spindle. The steering wheel hub supports the steering wheel rim which forms an annular or annular section-shaped grip element for the steering intervention. The steering wheel rim surrounds the steering wheel hub continuously or in sections at a spacing from the longitudinal axis, the grip element or elements being arranged in a planar arrangement substantially parallel to a rotational plane which lies perpendicularly with respect to the longitudinal axis. In the classic shape, the steering wheel rim can be of circumferential configuration in a round manner with a hoop-shaped grip element; in order to optimize the ergonomics and the design, it can have a shape which is flattened, rectangular or irregular, and continuous or interrupted over the circumference.
In the conventional, manual operating state, the steering wheel is positioned in the vehicle interior compartment, with the result that it can be reached comfortably by way of the driver for a manual steering intervention and can be operated in an ergonomically favorable manner. For this purpose, it is known to design the steering column to be adjustable longitudinally and vertically, with the result that the spacing and the height of the steering wheel can be set within a typical range of possible handling or operating positions. In the automated driving mode in the case of autonomous driving, the steering of the vehicle takes place in an automated manner on the basis of measured and predefined control parameters which set the steering angle of the wheels via electromechanical actuators, in order to follow a predefined steering trajectory. A manual steering intervention by way of the driver is no longer required, and the aim is correspondingly to move the steering wheel which projects into the vehicle interior compartment in the operating state into a stowed position outside possible handling positions of the operating position, in order for it to be possible for the vehicle interior compartment which becomes free as a result to be utilized in an alternative manner.
FR 2861657 A1 has disclosed a vehicle steering system, having a steering unit which has a steering wheel which is attached by way of its steering wheel hub on the steering spindle, a supporting unit for rotatably mounting the steering spindle, and an electronic sensor system for detecting steering commands. The entire steering unit can be positioned relative to the vehicle interior compartment in the longitudinal direction on a positioning apparatus, and can be inclined in its entirety on the positioning device. The complicated construction is a disadvantage here. Moreover, said steering system can be used exclusively for pure steer-by-wire steering systems, in the case of which no mechanical connection of the steering spindle to the wheels is provided.
In order for it to be possible for the steering wheel to be moved out of the handling region, what are known as “head tilt” steering systems are known, as described in EP 2 567 878 B1, for example. Here, the steering spindle is connected at its front end which is remote from the steering wheel via a universal joint to the steering shaft, and is mounted such that it can be tilted relative to the vehicle body around a tilt joint. As a result, the entire steering spindle including the steering wheel which is attached fixedly on it can be inclined forward. The complicated construction and the limited possibilities for stowing the steering wheel in the vehicle interior compartment are disadvantageous.
Thus a need exists for a steering wheel which makes improved stowing and more widespread possible uses possible, and which has a simpler construction which is as compact as possible.